Acupuncture mechanism and battery thermal runaway testing device

Abstract

The utility model discloses a needling mechanism and a battery thermal runaway testing device. The needling mechanism comprises a needle body, a heating piece and a first temperature sensor. The needle body is used for puncturing a to-be-tested battery; the heating piece and the needle body transfer heat; the first temperature sensor is used for acquiring the temperature in the to-be-measured battery. The acupuncture test is carried out under the high-temperature condition, and in order to track the temperature change in the battery in real time, the first temperature sensor is arranged in the embodiment, so that the temperature in the battery to be tested is obtained in real time. In this way, the internal temperature change of the to-be-measured battery at different pricking needle positions can be obtained. The needle body punctures at different temperatures, and the internal temperature of the to-be-tested battery is changed; the performance of the to-be-tested battery under extreme conditions can be obtained to the maximum extent through the needle body in different needling directions, the internal temperature change of the to-be-tested battery and the like, and higher safety and reliability of the battery in practical application are further ensured.

Description

Technical Field

[0001] The utility model generally relates to the technical field of lithium batteries, and particularly relates to a needle punching mechanism and a test device for battery thermal runaway. Background Art

[0002] For the safety test of lithium batteries, the needle punching experiment is the most complex.

[0003] In the related art, the needle punching test can well reflect the occurrence of battery short circuit. When the steel needle penetrates, the steel needle provides a path for internal short circuit of the battery. The electrical energy of the battery is converted into heat energy and stored inside the battery. The short circuit causes a concentrated explosion and release of energy in a short time, which may cause smoking, leakage, or even fire and explosion.

[0004] However, in the above test process, only the thermal runaway phenomenon triggered after the battery is punctured by the needle can be displayed, and the thermal runaway phenomenon of the battery caused by other reasons cannot be reflected, so there is room for improvement. Summary of the Utility Model

[0005] This application expects to provide a needle punching mechanism and a test device for battery thermal runaway, which are at least used to track the temperature change inside the battery in real time, obtain the internal temperature of the battery to be tested in real time, maximize the performance of the battery to be tested under extreme conditions, and further ensure higher safety and reliability of the battery in actual applications.

[0006] The utility model provides a needle punching mechanism, including: a needle body, a heating element and a first temperature sensor.

[0007] The needle body is used to pierce the battery to be tested; the heating element is in heat transfer with the needle body; the first temperature sensor is used to obtain the temperature inside the battery to be tested.

[0008] As an implementable manner, the needle body has a hollow structure, and the heating element is arranged inside the hollow structure.

[0009] As an implementable manner, the first temperature sensor includes a radiation thermometer,

[0010] The heating element has a through hole, the through hole includes a first opening and a second opening arranged oppositely, the first opening is close to the tip of the needle body, and the second opening is far from the tip of the needle body.

[0011] The infrared emission end of the radiation thermometer is arranged close to the second opening, and the infrared rays emitted by the infrared emission end pass through the tip of the needle tip, or the infrared rays emitted by the infrared emission end are located between the outer surface of the side wall of the heating element and the inner surface of the side wall of the needle body.

[0012] As an implementable manner, the cross-section of the needle body is circular, the cross-section of the through hole is circular, and the needle body is coaxially arranged with the through hole.

[0013] As an implementable manner, the first temperature sensor includes a first thermocouple temperature measuring wire, and the first thermocouple temperature measuring wire is wound on the outer surface of the side wall of the needle body and close to the tip of the needle body.

[0014] As an implementable manner, it further includes a second temperature sensor, and the second temperature sensor is used to obtain the temperature of the heating element.

[0015] As an implementable manner, the second temperature sensor includes a second thermocouple temperature measuring wire, the heating element includes a heating rod, and the second thermocouple temperature measuring wire is wound on the heating rod.

[0016] As an implementable manner, it further includes a battery fixture, and the battery fixture includes a third temperature sensor and a first clamping plate and a second clamping plate that are opposite and spaced apart.

[0017] The third temperature sensor is arranged on at least one of the surface of the first clamping plate facing the second clamping plate and the surface of the second clamping plate facing the first clamping plate, and a through hole capable of passing through the needle body is provided on one of the first clamping plate and the second clamping plate.

[0018] As an implementable manner, it further includes a pressing assembly, and the pressing assembly presses at least one of the first clamping plate and the second clamping plate.

[0019] As an implementable manner, it further includes a support frame, and the support frame includes a slide rail, and the length direction of the slide rail is parallel to the direction from the first clamping plate to the second clamping plate.

[0020] One of the first clamping plate and the second clamping plate is fixedly connected to the slide rail, and the other is matched with the pressing assembly, so that the first clamping plate and the second clamping plate can move towards each other and move away from each other.

[0021] As an implementable manner, there are a plurality of the slide rails, and the plurality of slide rails are arranged around the first clamping plate and the second clamping plate;

[0022] The pressing assembly includes a pressing telescopic member and a pressure sensor. The pressing telescopic member makes the first clamping plate or the second clamping plate reciprocate along the length direction of the slide rail, and the pressure sensor is used to obtain the pressure of the pressing telescopic member pressing the first clamping plate or the second clamping plate.

[0023] The present utility model also provides a test device for battery thermal runaway, including the above-mentioned needle punching mechanism.

[0024] In the above solution, a needle-punching test is carried out under high-temperature conditions. In order to track the temperature change inside the battery in real time, a first temperature sensor is set in this embodiment to obtain the internal temperature of the battery to be tested in real time. This helps to obtain the internal temperature change of the battery to be tested at different needle-punching positions; the internal temperature change of the battery to be tested when the needle body punches at different temperatures; the internal temperature change of the battery to be tested when the needle body punches in different directions, etc., to obtain the performance of the battery to be tested under extreme conditions to the greatest extent, and further ensure that the battery has higher safety and reliability in actual applications. The first temperature sensor can be a radiation thermometer, for example, an infrared thermometer, a brightness / monochromatic pyrometer. The infrared rays emitted by the infrared emission end can reach the tip of the needle tip, so that the infrared thermometer can obtain the temperature of the tip of the needle tip. The temperature of the tip can truly reflect the internal change of the innermost part of the battery to be tested, which helps to accurately obtain the internal temperature change of the battery to be tested. In addition, the infrared thermometer is not affected by the high temperature of the heating element, avoiding accidental damage to the infrared thermometer and helping it to work normally and stably. The first temperature sensor can be a first thermocouple temperature measurement wire. The first thermocouple temperature measurement wire is wound on the outer surface of the side wall of the needle body and is close to the tip of the needle body 10. Such a structure is simple and the cost is low. Description of the Drawings

[0025] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present application will become more obvious:

[0026] Figure 1 The front view schematic diagram of the needle-punching mechanism provided by the embodiment of the present utility model;

[0027] Figure 2 The three-dimensional structure schematic diagram of the needle-punching mechanism provided by the embodiment of the present utility model Figure 1 ;

[0028] Figure 3 The three-dimensional structure schematic diagram of the needle-punching mechanism provided by the embodiment of the present utility model Figure 2 ;

[0029] Figure 4 The cross-sectional schematic diagram of a kind of needle body provided by the embodiment of the present utility model;

[0030] Figure 5 The cross-sectional schematic diagram of another kind of needle body provided by the embodiment of the present utility model;

[0031] Needle body 10, hollow structure 101, needle rod 11, first cavity 1011, needle tip 12, second cavity 1012;

[0032] Heating rod 20, through hole 21, first opening 211, second opening 212;

[0033] The first temperature sensor 30, the infrared emission end 31, and the second temperature sensor 40;

[0034] The battery fixture 50, the first clamping plate 51, the through hole 511, the second clamping plate 52, and the third temperature sensor 53;

[0035] The pressing telescopic member 61, the pressing plate 62, the pressure sensor 63, the support frame 70, the slide rail 71, the sliding seat 80, and the battery under test 90. Specific embodiments

[0036] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant utility model and are not intended to limit the utility model. Additionally, it should be noted that for the convenience of description, only the parts related to the utility model are shown in the drawings.

[0037] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0038] At least refer to Figures 1 - 5 As shown, an example of the present utility model provides a needle punching mechanism, including: a support frame 70, a sliding seat 80, a battery fixture 50, a needle body 10, a heating member, and a first temperature sensor 30.

[0039] The needle body 10 is used to pierce the battery under test 90.

[0040] Among them, the needle body 10 can be, but is not limited to, carbon steel or stainless steel. The needle body 10 includes a needle rod 11 and a needle tip 12.

[0041] The needle body 10 is installed on the sliding seat 80. The support frame 70 includes a slide rail 71, and the sliding seat 80 is slidably matched with the slide rail 71, and the sliding seat 80 reciprocates along the length direction of the slide rail 71.

[0042] Specifically, as Figures 1 - 3 shown, the support frame 70 is provided with a plurality of slide rails 71, the plurality of slide rails 71 are arranged in parallel, and each extends along the left - right direction. The plurality of slide rails 71 can be arranged around the sliding seat 80, and the initial position of the sliding seat 80 is set near the left end of each slide rail 71. For example, two slide rails 71 are located above the sliding seat 80, and two slide rails 71 are located below the sliding seat 80. In this way, the slide rails 71 can limit the freedom degree of the sliding seat 80 in the up - down direction, which helps the sliding seat 80 to reciprocate only along the left - right direction.

[0043] Meanwhile, multiple sliding rails 71 can be arranged around the battery fixture 50, and the battery fixture 50 is arranged near the middle of each sliding rail 71. For example, two sliding rails 71 are located above the battery fixture 50, and two sliding rails 71 are located below the battery fixture 50.

[0044] The battery fixture 50 stably clamps the battery 90 to be tested. The sliding seat 80 moves from left to right along the sliding rail 71 until it pierces the battery 90 to be tested; finally, the sliding seat 80 returns from right to left along the sliding rail 71 to its initial position.

[0045] The heating element transfers heat to the needle body 10.

[0046] Among them, the heating element can heat the needle body 10 by means of radiation heating; the heating element can heat the needle body 10 by means of electric heating; the heating element can heat the needle body 10 by means of hot air heating; or, other suitable means can be used to heat the needle body 10.

[0047] The temperature of the heated needle body 10 can be between 45°C and 200°C.

[0048] In a specific embodiment, the needle body 10 has a hollow structure 101, and the heating element is arranged in the hollow structure 101.

[0049] For example, as Figure 4 shown, the needle rod 11 has a first cavity 1011, the needle tip 12 has a second cavity 1012, and the second cavity 1012 communicates with the first cavity 1011 to form a hollow structure 101. The cross-sections of the first cavity 1011 and the second cavity 1012 are circular.

[0050] The heating element can be a heating rod 20. The cross-section of the heating rod 20 is circular, and the heating rod 20 is coaxially arranged with the first cavity 1011 (or the second cavity 1012), so that the axis of the needle rod 11 and the axis of the heating rod 20 are on the same straight line. The heating rod 20 passes through the first cavity 1011, and one end of the heating rod 20 is located in the second cavity 1012.

[0051] Of course, it can be understood that the needle rod 11 can also be a solid structure.

[0052] When the heated needle body 10 pierces the battery 90 to be tested in this way, the high-temperature needle body 10 accelerates the deformation and softening of the diaphragm inside the battery until the diaphragm falls off. Since the diaphragm is a porous plastic film, its function is to isolate the positive and negative electrodes of the battery and prevent them from directly contacting and causing a short circuit. As a result, the positive and negative electrodes of the battery are in direct contact, or the steel needle contacts the aluminum foil inside the positive electrode tab, triggering a short-circuit discharge, which ultimately leads to the thermal runaway of the battery to be tested. At the same time, the high-temperature needle-piercing test, as a stringent test method, can more strictly test the safety performance of the battery and ensure the safety of the battery under extreme conditions; it can discover the weak links of the battery under extreme conditions, thereby optimizing the battery design. For example, by observing the reactions of the battery at different needle-piercing positions and directions, a safer battery structure can be designed to reduce the risk of thermal runaway.

[0053] As an implementable manner, the needle-piercing mechanism further includes a second temperature sensor 40 and a temperature controller (not shown). The second temperature sensor 40 is used to obtain the real-time temperature of the heating rod 20. The heating rod 20 is electrically connected to the temperature controller and the second temperature sensor 40 respectively. The second temperature sensor 40 obtains the temperature information and sends it to the temperature controller. The temperature controller compares the temperature information with the preset temperature to control whether the temperature of the heating rod 20 rises or falls.

[0054] In a specific embodiment, as Figure 4 or Figure 5 shown, the second temperature sensor 40 is a second thermocouple temperature measurement wire, and the second thermocouple temperature measurement wire is wound around the heating rod 20. In this way, the structure is simple and the cost is low.

[0055] Of course, it can be understood that the second temperature sensor 40 can be a radiation thermometer, for example, an infrared thermometer, a brightness / monochromatic pyrometer.

[0056] In the needle-piercing test under high-temperature conditions, in order to more intuitively observe the reactions inside the battery. For example, to perform real-time tracking of the temperature change inside the battery, a first temperature sensor 30 is set in this embodiment to obtain the internal temperature of the battery to be tested in real time.

[0057] This helps to obtain the internal temperature changes of the battery 90 to be tested at different needle-piercing positions; the internal temperature changes of the battery 90 to be tested when the needle body 10 pierces at different temperatures; the internal temperature changes of the battery 90 to be tested when the needle body 10 pierces in different directions, etc., to maximize the performance of the battery 90 to be tested under extreme conditions, and further ensure that the battery has higher safety and reliability in actual applications.

[0058] As an implementable manner, the first temperature sensor 30 can be a radiation thermometer, for example, an infrared thermometer, a brightness / monochromatic pyrometer.

[0059] In a specific embodiment, as Figure 4 shown, the heating rod 20 has a through hole 21. The axis of the through hole 21 is coaxially arranged with the axis of the first cavity 1011, and the axis of the through hole 21 passes through the tip of the needle tip 12.

[0060] The through hole 21 includes a first opening 211 and a second opening 212 which are oppositely arranged. The first opening 211 faces right, and the first opening 211 is close to the needle tip 12 of the needle body 10; the first opening 211 faces left, and the second opening 212 is far from the needle tip 12 of the needle body 10. The infrared emission end 31 of the infrared thermometer is arranged close to the second opening 212, and the infrared ray emitted by the infrared emission end 31 coincides with the axis of the through hole 21. In this way, the infrared ray emitted by the infrared emission end 31 can reach the tip of the needle tip 12, so that the infrared thermometer can obtain the temperature of the tip of the needle tip 12. Since the tip of the needle tip 12 is at the deepest position of the battery 90 to be measured, the temperature of the tip can truly reflect the internal change of the innermost part of the battery 90 to be measured, which helps to accurately obtain the internal temperature change of the battery 90 to be measured.

[0061] In addition, the infrared thermometer will not be affected by the high temperature of the heating rod 20, avoiding accidental damage to the infrared thermometer and helping it to work normally and stably.

[0062] Of course, it can be understood that the axis of the through hole 21 and the axis of the first cavity 1011 can be arranged non-coaxially. The infrared ray emitted by the infrared emission end 31 can be located between the outer surface of the side wall of the heating rod 20 and the inner surface of the side wall of the needle body 10, and the infrared ray reaches the remaining position of the needle tip 12 except the tip.

[0063] As an implementable manner, the first temperature sensor 30 can be a first thermocouple temperature measuring wire.

[0064] In another specific embodiment, as Figure 5 shown, the first thermocouple temperature measuring wire is wound around the outer surface of the side wall of the needle body 10 and is close to the needle tip 12 of the needle body 10. The temperature suitable for the first thermocouple temperature measuring wire can be between 1300°C and 1600°C. In this way, the structure is simple and the cost is low.

[0065] As an implementable manner, the battery fixture 50 includes a third temperature sensor 53 and a first clamping plate 51 and a second clamping plate 52 which are opposite and spaced apart. The third temperature sensor 53 is arranged on at least one of the surface of the first clamping plate 51 facing the second clamping plate 52 and the surface of the second clamping plate 52 facing the first clamping plate 51.

[0066] As Figures 1 - 3 shown, the first clamping plate 51 and the second clamping plate 52 are opposite and spaced apart in the left-right direction. The distance between the first clamping plate 51 and the second clamping plate 52 can be adjusted.

[0067] The third temperature sensor 53 is a thermocouple. One third temperature sensor 53 is mounted on the right surface of the first clamping plate 51, and another third temperature sensor 53 is mounted on the left surface of the second clamping plate 52. The two third temperature sensors 53 are in contact with the two surfaces of the battery 90 to be measured, so as to obtain the surface temperature of the battery 90 to be measured at all times.

[0068] Furthermore, one of the first clamping plate 51 and the second clamping plate 52 is provided with a through hole 511 that can pass through the needle body 10.

[0069] As Figure 2 shown, the first clamping plate 51 is close to the needle body 10. The first clamping plate 51 is fixedly connected to each slide rail 71, and a through hole 511 is provided at the center position of the first clamping plate 51. In this way, the through hole 511 has a guiding effect on the needle body 10, which helps the needle body 10 to pass through and pierce the battery 90 to be measured.

[0070] As an implementable manner, the needle punching mechanism further includes a pressing assembly 60, and the pressing assembly 60 presses at least one of the first clamping plate 51 and the second clamping plate 52.

[0071] As Figures 1 - 3 shown, the sliding seat 80, the battery fixture 50, and the pressing assembly 60 are arranged in sequence in the left-to-right direction, and the pressing assembly 60 is arranged near the right end of each slide rail 71.

[0072] Each slide rail 71 is arranged around the pressing assembly 60. The cooperation between the pressing assembly 60 and the second clamping plate 52 enables the second clamping plate 52 and the first clamping plate 51 to move towards each other and move away from each other.

[0073] Specifically, as Figure 3 shown, the pressing assembly 60 includes a pressing telescopic member 61, a pressing plate 62, and a pressure sensor 63. The pressing telescopic member 61 makes a linear reciprocating motion. The pressing telescopic member 61 can be an electric push rod, a hydraulic push rod, a pneumatic push rod, a crank-slider mechanism, ……, which are not listed one by one in this embodiment.

[0074] Taking the electric push rod as an example: The movable end of the electric push rod is connected to the pressing plate 62, the pressing plate 62 is connected to the second clamping plate 52, and a pressure sensor 63 is provided between the pressing plate 62 and the second clamping plate 52. When the movable end of the electric push rod moves to the left, it drives the second clamping plate 52 to approach the first clamping plate 51 until the battery 90 to be measured is pressed between the second clamping plate 52 and the first clamping plate 51. When the needle body 10 pierces the battery 90 to be measured, the battery 90 to be measured is stably kept stationary.

[0075] In order to further simulate the application of the battery 90 to be tested in an actual scenario and further ensure that the battery has higher safety and reliability in actual application

[0076] The electric push rod further causes the second clamping plate 52 to press against the battery 90 to be tested, so that the acting forces of the first clamping plate 51 and the second clamping plate 52 on the battery 90 to be tested are further increased to simulate the extrusion situation of the battery in actual application.

[0077] Meanwhile, the pressure of the pressing telescopic member 61 pressing against the second clamping plate 52 is obtained in real time through the pressure sensor 63, so that a preset pressure value can be applied to the battery 90 to be tested, and the pressure value can be 0.1 kN to 25 kN.

[0078] The exemplary embodiment of the present invention further provides a test device for battery thermal runaway, and the test device includes the above-mentioned acupuncture mechanism. Since the test device has the advantages of the acupuncture mechanism, it will not be described in detail here.

[0079] It should be understood that if the above text involves terms such as "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0080] The above description is only a preferred embodiment of the present application and an explanation of the applied technical principle. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in the present application.

Claims

1. An acupuncture mechanism, characterized in that: include: A needle body (10) used for piercing the battery to be tested (90); A heating element, wherein the heating element transfers heat to the needle body (10); A first temperature sensor (30), the first temperature sensor (30) is used to obtain the internal temperature of the battery to be tested (90).

2. The acupuncture mechanism according to claim 1, characterized in that: The needle body (10) has a hollow structure (101), and the heating element is arranged in the hollow structure (101).

3. The acupuncture mechanism according to claim 2, characterized in that: The first temperature sensor (30) comprises a radiation temperature sensor, The heating element has a through hole (21), the through hole (21) comprising a first opening (211) and a second opening (212) arranged opposite to each other, the first opening (211) being close to the needle tip (11) of the needle body (10), and the second opening (212) being far from the needle tip (11) of the needle body (10), The infrared emitting end (31) of the radiation thermometer is arranged close to the second opening (212), and the infrared ray emitted by the infrared emitting end (31) passes through the tip of the needle tip (11), or the infrared ray emitted by the infrared emitting end (31) is located between the outer surface of the side wall of the heating element and the inner surface of the side wall of the needle body (10).

4. The acupuncture mechanism according to claim 3, characterized in that: The cross section of the needle body (10) is circular, the cross section of the through hole (21) is circular, and the needle body (10) and the through hole (21) are coaxially arranged.

5. The acupuncture mechanism according to claim 1 or 2, characterized in that: The first temperature sensor (30) comprises a first thermocouple temperature measuring wire, which is wound around the outer surface of the side wall of the needle body (10) and is close to the needle tip (11) of the needle body (10).

6. The acupuncture mechanism according to claim 2, characterized in that: It also includes a second temperature sensor (40), which is used to obtain the temperature of the heating element.

7. The acupuncture mechanism according to claim 6, characterized in that: The second temperature sensor (40) comprises a second thermocouple temperature measuring wire, the heating element comprises a heating rod (20), and the second thermocouple temperature measuring wire is wound around the heating rod (20).

8. The acupuncture mechanism according to claim 1, characterized in that: The battery clamp (50) further comprises a third temperature sensor (53) and a first clamping plate (51) and a second clamping plate (52) which are arranged opposite to each other and spaced apart. The third temperature sensor (53) is arranged on at least one of the surface of the first clamping plate (51) facing the second clamping plate (52) and the surface of the second clamping plate (52) facing the first clamping plate (51), and one of the first clamping plate (51) and the second clamping plate (52) is provided with a through hole (511) capable of passing the needle body (10).

9. The acupuncture mechanism according to claim 8, characterized in that: It also includes a pressing component (60), wherein the pressing component (60) presses at least one of the first clamping plate (51) and the second clamping plate (52).

10. The acupuncture mechanism according to claim 9, characterized in that: The device further comprises a support frame (70), wherein the support frame (70) comprises a slide rail (71), wherein the length direction of the slide rail (71) is parallel to the direction from the first clamping plate (51) to the second clamping plate (52), One of the first clamping plate (51) and the second clamping plate (52) is fixedly connected to the slide rail (71), and the other cooperates with the pressing assembly (60), so that the first clamping plate (51) and the second clamping plate (52) can move toward each other and move away from each other.

11. The acupuncture mechanism according to claim 10, characterized in that: A plurality of the slide rails (71) are provided, and the plurality of the slide rails (71) are arranged around the first clamping plate (51) and the second clamping plate (52); The pressing assembly (60) comprises a pressing telescopic member (61) and a pressure sensor (63). The pressing telescopic member (61) causes the first clamping plate (51) or the second clamping plate (52) to reciprocate along the length direction of the slide rail (71). The pressure sensor (63) is used to obtain the pressure of the pressing telescopic member (61) pressing the first clamping plate (51) or the second clamping plate (52).

12. A battery thermal runaway testing device, characterized in that: The invention comprises the acupuncture mechanism according to any one of claims 1 to 11.

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